More Evidence That Russia Supplied DPRK Rocket Engines And/Or Data

I quizzed a colleague who is well read in the arms control area, as Yuzhnoe’s comments were diametrically opposed to Elleman’s comments. Why? I summarize his off-the-record comments here.

Again, Yuzhnoye is the Ukrainian rocket engine designer.

Yuzhnoye made an interesting comment, that the DPRK engine is “open cycle”, where the turbopump efflux gas is vented. In this case, it could be via the four vernier steering nozzles. They argue that Ukrainian engines are “closed cycle”, where the turbopump efflux is routed into the main nozzle, and steering effected by nozzle gimbal tilting.

This is interesting as the DPRK engine using vernier nozzles looks much like the engine in the original R-36 / SS-9 SCARP series, the ancestor to the R-36M / SS-18 SATAN series. In the R-36 / SS-9 SCARP engine package, a four chamber four nozzle RD-68M vernier engine was used to steer the missile. In the later R-36M / SS-18 SATAN, the four RD-263 main engines (called an RD-264), were individually steered to control the missile.

Yuzhnoye may be right that the DPRK engine is open cycle, but it also might be a copy of the Soviet SS-9 SCARP engine, using a closed cycle RD-250/260 series main engine and a separate RD-68M clone for steering.

The punchline is that RD-263 engine hardware sourced from Russia could be adapted, and moreover, as the SS-9 SCARP was retired during the early 1980s, design data for this 1960s dinosaur could have been made available to the DPRK no differently than the R-27 SERB data was provided to the DPRK by Russia during the 1990s.

So the plot thickens.

The big and central question is why does the DPRK ICBM engine so closely resemble ancient 1960s Soviet engines? Design and manufacturing data for these 1960s Soviet ICBM engines would be archived in Russia. The stock of newer variants of these engines appears to be mostly or wholly held in Russia.